Intussusception

Question 1

Define intussusception

Answer 1

Invagination of the proximal bowel into a distal segment (prolapse of one part into the lumen of the adjoining distal part)
Most commonly involves the ileum passing into the caecum through the ileocaecal valve

Question 2

What is the aetiology of intussusception

Answer 2

The intussusceptum telescopes INTO the lumen of the intussuscipiens

The lead point of the intussusception is most often an enlarged mesenteric lymph node (Peyer’s patch) in the terminal ileum
Viral infection → hyperplasia of the Peyer’s patches and lymphoid tissue in the intestinal wall
Idiopathic

Question 3

Why can intussusception lead to ischaemia

Answer 3

The mesentery is dragged alongside the proximal bowel wall into the distal lumen → obstruction of venous return → oedema, muscosal bleeding, increased pressure
Arterial compromise → ischaemia, necrosis, perforation

Question 4

What may act as the pathological lead point for intussusception

Answer 4

Luminal polyps
Malignant tumours
Benign mass lesions e.g. lipomata
Meckel’s diverticulum
Henoch-Schonlein purpura (intestinal wall haematoma)
Enteric duplication cysts
Appendix
Hypertrophies mucosal glands (cystic fibrosis)

Question 5

What are the risk factors for intussusception

Answer 5

6-12 months
Male sex
Antecedent viral illness
First-generation rotavirus vaccination (RRV-TV)

Question 6

What are the symptoms of intussusception

Answer 6

Abdominal pain
- Paroxysmal, severe colicky pain
- 1-3- minutes
- Episodes of pain: child becomes pale, draws up legs, pain around the mouth
- Infant is normal between episodes
- >3 months (rule out colic)
Lethargic
Poor feeding
Vomiting (may be bile-stained depending on the site of intussusception)
Redcurrant jelly-like stools (blood-stained mucous) - represents mucosal oedema/ulceration
Abdominal distension

Question 7

What are the differentials for intussusception

Answer 7

Gastroenteritis
incarcerated inguinal hernia
Appendicitis
Mesenteric adenitis
Meckel’s diverticulum
Colic
Pyloric stenosis
Urinary tract infection

Question 8

What are the signs of intussusception on examination

Answer 8

Obs: shock (from intestinal ischaemia, gangrene, perforation)

General
Pale, draws legs up
Lethargic

abdominal
Sausage-shaped mass in the RUQ or epigastrum
Abdominal distension
Dance’s sign (emptiness on palpation of RUQ)

DRE
Blood on gloves

Question 9

What investigations should be done for intussusception

Answer 9

Urine dip
Blood glucose

FBC, CRP, LFTs, blood gas

Abdo US: Target/doughnut sign (single hypoechoic ring with hypoechoic centre)
AXR: distended small bowel, absent gas in distal colon or rectum, assess for perforation/obstruction
Diagnostic enema: meniscus sign

Question 10

What is the management for intussusception in a patient who is stable

Answer 10

1. IV fluid resuscitation
2. Contrast (barium/Gastrograffin) or air enema reduction

Second line: Surgical reduction + Abx (clindamycin, gentamycin)

Question 11

What is the management for intussusception in a patient who is unstable

Answer 11

1. A-E assessment
2. Contact paed surgeons
3. IV fluid resuscitation
4. NBM + NG feeds
5. Rectal air insufflation by the radiologist - CI in peritonitis, perforation, shock

Second line: surgical reduction

Question 12

What is the management for recurrent intussusception

Answer 12

Assess for a potential pathological lead point → CT abdomen

Question 13

What are the complications of intussusception

Answer 13

Bowel perforation
Peritonitis
Gut necrosis

Question 14

What is the prognosis for intussusception

Answer 14

Success rate of rectal air insufflation is about 75%
Recurrence of the intussusception occurs in less than 5% but is more frequent after hydrostatic/contrast enema reduction (10%)
Mortality in intussusception is related to delay in presentation, septic shock, and inadequate fluid resuscitation